MICROORGANISMS AS POTENTIAL SOURCES OF NOVEL DIPHENOL OXIDASE INHIBITORS

Culture filtrates and mycelial homogenates from over 100 microorganisms were tested for their ability to inhibit catecholase and laccase (o- and p-diphenol oxidase) activity using simple, rapid, colorimetric assays in microtiter plates or polarographic assays using an O₂-electrode. Of the organisms screened, 56 produced inhibition of catecholase activity and 34 gave rise to laccase inhibition, with most of the latter group showing inhibition of both enzymes. The role of this enzyme inhibitor system in plant pathogenicity is also discussed.     

Effect of Electrical Charge on Attachment of Salmonella typhimurium to Meat Surfaces

Treating tissue with electrical current was found to affect both the initial attachment and total numbers of attached Salmonella typhimurium to meat tissues. When lean tissue was attached to the positive terminal of the power supply operating at 50 volts/125 mA DC, the total number of attached cells increased. There was no effect when the samples were attached to the negative terminal. There was a significant (P<0.05) effect on the percentage of strongly attached bacteria with an increase in treating time. Electrical current was found to increase the percentage of strongly attached cells immediately after the current was applied.     

The United Kingdom's view of the market in Europe

The steps taken by Dairy Crest to investigate and establish a market for British cheese in Europe are described. From the initiation of the export campaign in 1980, development has been good, providing useful returns although the size of the market is still small compared to that of more traditional European exporters.     

Effect of Elevated CO2 Growth Conditions on the Nutritive Composition and Acceptability of Baked Sweet Potatoes

‘Georgia-Jet’ sweet potatoes were grown at CO₂ concentrations of 354, 431, 506, and 659 ppm for 90 days. Elevated CO₂ concentrations decreased protein, total carotenoids and insoluble dietary fiber. An increase in dry matter and a reddish-orange color was observed at 506 and 659 ppm CO₂ concentrations. Sensory evaluation scores for flavor and moistness indicated that sweet potatoes grown under high CO₂ concentrations were acceptable and not different from the control.     

CONTROL OF BACILLUS CEREUS IN HIGH-pH CRUMPETS

Studies were performed to determine the effects of sorbic hydroxamic acid (SHA) and mastic oil–ethanol (ME) or water‐ethanol (WE) emitters on the growth of Bacillus cereus in high‐moisture, high‐pH (～8.9) English‐style crumpets stored at ambient temperature (25C). While SHA (3000 p.p.m.), alone or in combination with ME emitters, was effective in inhibiting the growth of B. cereus for 14 days in high‐pH crumpets, only SHA formulated crumpets packaged in air had acceptable sensory scores at the end of storage. However, ME emitters alone were ineffective in controlling the growth of this pathogen. This lack of inhibition in crumpets was attributed to the poor absorption of mastic volatiles from the package headspace into the food matrix. Whatever the reason, these preliminary studies showed that SHA has the potential to control the growth of B. cereus in high‐moisture, high‐pH crumpets without compromising product quality.